In-situ Experimental Investigation on Pullout Performances and Horizontal Bearing Properties of Bored Piles

Abstract

By combination of practical engineering, the slow maintenance loading method was employed to conduct the field static load test studies of vertical pullout performance and horizontal bearing characteristics for single bored pile. According to the inclinometer pipes embedded in the bored pile during the construction, the variation laws of deep horizontal displacement of pile was investigated in the process of foundation pit excavation. The main conclusions can be summarized as: (1) in the vertical pullout test of single pile, the rates of deformation of pile top under the loading and unloading have some discrete and volatility; (2) in the horizontal static load test of single pile, the relationship between horizontal load and horizontal displacement is nonlinear; (3) the site monitoring shows that the horizontal deformation on the retaining pile top is large, and there is a significant inflection in the position where the steel supporting is installed. In addition, the most dangerous part is not on top of the retaining pile, but at 1/2 ~ 5/6 depth of foundation pit.